Electrobiorremediación de cutting para la biodegradación de hidrocarburos aromáticos policíclicos

The increasing demand for petroleum products has resulted in harmful environmental consequences, including the generation of oil exploitation waste, such as cuttings. Cuttings are complex matrices containing polycyclic aromatic hydrocarbons (PAHs) and heavy metals. This study aimed to evaluate the efficiency of electrobioremediation (EB) for PAH degradation in cutting samples, analyzing the influence of physicochemical parameters, heavy metal content, and the behavior of the indigenous bacterial community. A laboratory-scale electrochemical cell was used to treat cutting samples. For 60 days, cutting samples without nutrients and those enriched with nutrients (nitrogen and phosphorus) at a C:N:P ratio of 100:1:0.1 were treated using EB cells with a constant voltage gradient of 0.5 V cm-1. PAHs and heavy metals analyses, bacterial enumeration, identification via FAMEs, and analysis of the bacterial community by DGGE were performed. EB treatment showed effective PAH degradation compared to control systems, achieving degradation rates ranging from 15 % to 91 % in the EB system with nutrient addition. After 60 days of treatment, higher PAH removal was observed at sites near the electrodes (A3 and B3). Elevated barium concentrations did not adversely affect the indigenous bacterial community, which remained in optimal conditions for degradation. Chemical properties (conductivity, inorganic ions, pH, moisture, and temperature) and changes in the microbial community structure were fundamental to explain the degradation in different systems.